Self-Assembly Control of Y-Series Non-fullerene Acceptors for Sustainable and Scalable Organic Photovoltaics

Abstract Sustainability and scalability remain critical hurdles for the commercialization of organic solar cells (OSCs). However, addressing both poses challenge. Herein, we introduce a simple yet effective strategy utilizing 3,5-dichloropyridine (PDCC) as a solid additive to fine-tune the self-assembly behavior of Y-series non-fullerene acceptors (NFAs) to tackle the upscaling limitations in green-solvent-processed OSCs. PDCC predominantly interacts with Y-series NFAs, facilitating molecular crystallization and thereby driving the self-assembly of Y-series NFAs during film-forming dynamics, leading to more uniform active layers with improved molecular packing and reduced charge recombination. As a result, PDCC-driven self-assembly strategy enables high-performance OSCs with a power conversion efficiency (PCE) of 20.47%. When translated to sustainable fabrication, this strategy significantly boosts the PCE of large-area green-solvent-processed OSC modules (19.3 cm 2 ) from 13.87% to 15.79%, ranking it among the best-performing green-solvent-processed large-area OSC modules (> 18 cm 2 ). Beyond its impact on PCE enhancement, PDCC serves as a multifunctional additive to improve long-term stability and exhibits strong universality across multiple material systems. This work establishes a promising approach for advancing sustainable and scalable OSCs, paving the way for their commercialization.